In 2005, 212,000 new cases of breast cancer are expected, and approximately 40,000 women will die of the disease.1 Recent national figures indicate that approximately 45% of patients with breast, cancer undergo primary surgical treatment with mastectomy.2 The use of breast conserving treatment (lumpectomy and radiation therapy; BCT) is increasing as primary surgical treatment for breast cancer as long term studies have documented the efficacy of BCT.3 BCT is often followed by systemic therapy with chemotherapy, hormone therapy, or both. A prerequisite for BCT is complete removal of the cancer, documented by negative margins on pathologic evaluation of fee lumpectomy specimen. The presence of positive margins is associated with increased local recurrence (LR) rates, 10-15% vs. 1-10% with negative margins.4 A competing interest is the preservation of breast tissue to minimise deformity.
The importance of local recurrence is controversial. Early studies suggested that LR does hot translate into death from disease.4 However, recent data showing lower LR rates and survival benefit by adding radiation therapy to mastectomy for patients with higher stage cancers indicate the potential importance of freedom from local recurrence.5 In addition, LR contributes to significant local, morbidity, usually requiring a mastectomy. Finally LR contributes to the cost of care and anxiety for the patient. Despite these issues. 20-60% of patients undergoing BCT are found to have positive margins requiring additional surgical procedures, either re-excisional lumpectomies, or mastectomy.6 These additional procedures result in increased cost, increased anxiety for the patient, and, importantly, a delay in initiation of important systemic chemotherapy or radiation therapy.
Although many patients undergoing excisional breast biopsy are found to not have cancer, the wider use of pre-operative core needle biopsy has increased the preoperative diagnosis of invasive breast cancer (SBC) or ductal carcinoma in situ (DOS). At operation, the surgeon attempts to completely resect the cancer with negative microscopic margins, but feces several difficulties, DOS often is associated with grossly normal appearing breast tissue and no mass. Breast cancers presenting as a mass allow the surgeon to feel and see the area to be excised. However, the microscopic extent of disease is difficult to gauge. Frozen section analysis of breast biopsy margins is difficult and unreliable, because the fat content of breast tissue results in difficulty in sectioning frozen specimens. Even after standard tissue preparation over 2 days, one estimate is that more than 1,000 slices of a 2 cm biopsy specimen would be necessary to ensure completely negative, margins. Pathologists have attempted to peel the external surface of a permanently fixed specimen, as one might peel an orange, to evaluate the entirety of the specimen margin. This is difficult, and impractical in most institutions, but also does not provide real time information while the patient is in the operating room.
For all of these reasons, surgeons have adopted several techniques to increase the likelihood of negative margins. They may ink the entire specimen with a single colored ink in the operating room or in the pathology suite with the pathologist. More recently, multiple colored inks have been used to mark the six sides of a cuboid breast specimen. The former method does not allow re-resection of a specific positive margin and results in resection of a larger volume of breast tissue since the cavity side with a positive margin is not known. With both approaches, the ink may creep into crevices, resulting in falsely positive margins. With fee multi-colored approach, inks may run together, resulting in confusion as to the location of a specific positive margin.
Many surgeons perform wide excisions, potentially resulting in significant breast deformity that is added, to by the breast, shrinkage associated with radiation therapy. An effective and widely used method to enhance the likelihood of negative margins requires the surgeon, after excision of the tumor bearing specimen, to take additional slices of breast tissue from the four sides aid deep surface of the open breast cavity, and submit these additional “margins” separately as the final margins. This approach eliminates any confusion as to the location of the margin. When this technique is used, additional cancer is found in 20% of additional margins when the margins of the original specimen were negative.5 Regardless of the technique, final pathology evaluation may take up to one week. This delay results in patient anxiety and longer time to completion of the patient's surgical treatment. A method for reliable, infra-operative margin evaluation would be of great value for breast cancer surgery.
Sentinel lymph node biopsy (SLNB) has replaced elective lymph node dissection (ELND) of the ipsilateral axilla for patients with invasive breast cancer. Because of fee high negative predictive value of SLNB patients with negative sentinel nodes are spared the need for a complete axillary dissection, with its attendant morbidity and cost. Patients with positive nodes may undergo complete axillary dissection synchronously if a frozen section pathology report is positive. The accuracy of sentinel node evaluation by frozen section is problematic,6 with a significant false negative risk, when compared to the final report. To avoid giving patients bad news after an initial favorable report, many surgeons avoid frozen section entirely, waiting up to a week for the final pathology evaluation to decide whether a patient needs additional surgery. That additional surgery may take place 1-2 weeks later. Lymph, nodes containing malignant, cells may have altered blood flow, which may fee seen by Hyperspectral imaging. A reliable, real time method which accurately predicts lymph node metastasis would allow synchronous and complete management of the axilla, and reduce or eliminate additional anesthesias and operations.7 
Lymphomas, which include Hodgkin's disease and noo-Modgkin's lymphoma, are the fifth most common type of cancer diagnosed and the sixth most common cause of cancer death in the United States. Of the two basic lymphoma types, non-Hodgkin's lymphoma is the more common, with 16,000 new cases diagnosed annually.8 The age-adjusted incidence rate of non-Hodgkin's lymphoma among non-Hispanic white men (the demographic group with the greatest preponderance) is 19.1 per 100*000 and among non-Hispanic white women are 12.0 per 100,000. Not unexpectedly, incidence rates increase with age, with a 5-fold increase from ages 30-54 to 70 and older for non-Hispanic white men, hut 16-fold among Filipino women, the group with the greatest increase. However, leukemia and lymphoma also account for about half of the new cancer cases in children. Preclinical detection and intervention are likely to achieve a reduction in these rates. Patients already treated for lymphoma are at the greatest risk. Significantly, a study of patients monitored intensively for relapse (by physical examination, serum, analysis, chest X-ray, gallium and CT scanning, ultrasound and hone marrow biopsy) determined feat, in 91% of patients, relapse was detected at unscheduled visits for symptomatic disease.9 Furthermore, standard chemotherapy is effective in only 40% of patients. Clearly, new and more effective measures are needed, such as high resolution hyperspectral imaging of physiologic biomarkers for early detection of relapse.
A method, for now-invasive evaluation of the progression of non-Hodgkin's lymphoma (NHL) and responses to therapy would be highly advantageous, having utility as both a non-destructive animal research, tool, and as a non-invasive clinical tool, which greatly improve diagnostic efficiency. Disease progression can be evaluated in solid tissue such as the spleen and from monitoring leukemic cells in blood and lymph nodes. In addition to monitoring systemic microvascular effects induced by the disease.
Differentiating between types of tissue is useful in the medical and surgical arenas. This includes differentiating between types of normal tissue or between varieties of normal tissue types and distinguishing them from tumor tissue.